1. Field of the Invention
The invention relates generally to the field of electrodes for medical treatment. More particularly, the invention relates to a wire based electrode that is provided with a temperature sensing capability without necessarily needing to use any hollow tubing to accommodate the corresponding temperature sensor lead.
2. Discussion of the Related Art
Prior art temperature sensing electrodes, sometimes called temperature sensing energy delivery devices, are known to those skilled in the art. For example, a conventional temperature sensing electrode is typically constructed by threading a thermocouple cable through the central axis of a hollow tube and fixing the junction of the thermocouple to a sharpened tip at a distal end of the hollow tube.
Referring to FIG. 1, a conventional temperature sensing electrode is shown. A stainless steel tube 100 is provided with a sharpened tip 110. The junction 120 of a thermocouple 130 is attached to the interior of the stainless steel tube 100 with an adhesive 140. The thermocouple 130 includes a first wire 140 of a first metal material and a second wire 150 of a second metal material.
A problem with this temperature sensing electrode technology has been that using a hollow tube to accommodate the thermocouple cable reduces the strength of the electrode, compared to a non-temperature sensing, solid wire electrode of equal outer diameter. In the past, in order to address this reduction in strength, the size (i.e., inner and outer diameter) of the hollow tubing was increased to achieve the necessary mechanical strength. However, this scaling-up approach has the twin drawbacks of creating a larger surgical instrument that is more difficult for the surgeon to manipulate and an instrument which cuts a larger hole when inserted into tissue, thereby increasing the invasiveness of a given surgical procedure. Therefore, what is required is a solution that provides a temperature sensing capability in an electrode without increasing the bulk of the electrode.
Another problem with this temperature sensing electrode technology has been that the available hollow tubing that is suitable for surgical insertion into tissue (i.e., tubing having suitable mechanical and corrosion properties) is expensive. In the past, the high cost of hollow tubing based electrodes has simply been endured, thereby inhibiting the wider deployment of temperature sensing electrodes within the surgical community. Therefore, what is also required is a solution that allows the fabrication of a temperature sensing electrodes at lower cost, preferably a much lower cost.
Heretofore, the requirements of accommodating a temperature sensor and the corresponding temperature sensor lead, providing sufficient strength without bulk, and lower cost referred to above have not been fully met with regard to temperature sensing electrodes. What is needed is a solution that simultaneously addresses all of these requirements.